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Update on the Northwest Regional Modeling System 2015. Cliff Mass and David Ovens University of Washington. Goal and sponsors. To produce state-of-the-art, high-resolution numerical weather forecasts over the Pacific Northwest.
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Update on the Northwest Regional Modeling System 2015 Cliff Mass and David Ovens University of Washington
Goal and sponsors • To produce state-of-the-art, high-resolution numerical weather forecasts over the Pacific Northwest. • Supported by NW Modeling Consortium: a collection of local, state, and Federal Agencies AND the private sector (King-5)
NW High Resolution Regional Prediction • Currently runs with 36, 12, 4, and 1.3 km grid spacing using the WRF (Weather Research and Forecasting) ARW model twice a day at 0000 and 1200 UTC (5 AM and 5 PM PDT) • One of the highest resolution numerical weather prediction efforts in the U.S. • Physics tested to work best in our region.
UW Model Graphics on KING TV King-5 is getting our model grids and creating on-air graphics.
New Computers! • The server (SAGE) was completely refreshed • 8 20-core nodes (2 x 10 cores), each with 64 GB RAM. 160 cores total. • Head node has 128 GB RAM and solid state drive • The machine is roughly twice as fast as old one (1.84x).
Forecasts Available Earlier With New Computers • 4/3 km now done by 1:30 PM/AM instead of 5 PM. • 26/12/4/ done around 9 AM/PM.
Major Upgrade to WRF modeling system (Jan. 29, 0000 UTC run) • Tested dozens of combinations of upgrades and parameterizations for all seasons. • Upgraded to new version of WRF (3.5.1 to 3.6.1) • Moved from the NOAH to NOAH MP land surface model. NOAH MP (multi-physics) has much more sophisticated treatment of surface and hydrological processes, like snow.
RAP Initialization • We have been initializing with the National Weather Service GFS global model grids (1 or .5 degree resolution grids). Little mesoscale detail, so our model would have to spin things up. • Furthermore, we were using the initialization grids from a very different modeling system (GFS), resulting in additional spin-up issues.
RAP Initialization • In the new system we use the initialization from the 13-km NOAA Rapid Refresh model that is based on WRF. • Less difference in modeling system (also WRF) results in less spin up • Much more mesoscale detail. • Better initialization of clouds and boundary layer structures. • Rapid Refresh uses all available mesoscale data sources
Old New Big differences over Puget Sound. Which is right?
Seattle Sand Point Soundings Old New
Latest verifications look favorableWind direction, winds > 3 knots